Among Aquatic Animals,only the Blood of ________ is Nearly Isotonic

Question

Among aquatic animals,only the blood of ________ is nearly isotonic to seawater.
A)whales
B)freshwater bony fish
C)marine bony fish
D)cartilaginous fish
E)salamanders

Accepted Answer

Cartilaginous fish, such as sharks and rays, have blood that is nearly isotonic to seawater due to the presence of high concentrations of urea and trimethylamine oxide, which help maintain osmotic balance with their environment.